The present invention relates to a continuous-type emitter for distributing water in a constant flow rate. In particular, the present invention provides means for water distribution by using for example a pressure compensating strip such as a continuous emitter having a first profiles and a second profiles in a regulating section, thus allows for excellent fine-tuning of water flow rate and water pressure regulation.
There are several types of irrigation systems widely used nowadays, depending on how the water is distributed throughout the field. Some common types of irrigation systems include, for example, surface irrigation, sprinkler irrigation and localized irrigation. In surface irrigation, water is distributed over and across land by gravity, and no mechanical pump involved. In sprinkler irrigation, water is distributed by overhead high-pressure sprinklers or guns from a central location in the field or from sprinklers on moving platforms.
These systems have numerous shortcomings, including inefficient use of water and fertilizers, poor water distribution and poor uniformity of water application on steep or uneven terrain. In view of these shortcomings, localized irrigation has been developed, where water is distributed under low pressure, through a piped network and applied to each plant.
Drip irrigation is a type of localized irrigation in which drops of water are delivered at or near the root of plants. In this type of irrigation, evaporation and runoff are minimized. A type of discrete emitter has been widely used in the drip irrigation system. However, such discrete emitter often consists of multiple parts, thus entails higher production cost, and therefore is less favorable in some instances due to economical reasons.
Discrete emitters are commonly being used when a larger distance of water outlets are required, for instance a water outlet in about every 20 cm or more for each segment water outlet. In this case, discrete emitters are more economically to be used compared to a continuous emitter. When water outlets are needed to be repeated in a shorter distance, for example less than every 20 cm, an elongated emitter is advantageously a more favorable option.
On another hand, some types of continuous emitter may consist of flexible tunnel-like emitter. Said tunnel-like emitter reduces water pressure (and hence water outflow rate) when, water pressure of the hose is high. However, such type of flexible emitters face problems of higher fluctuation of water outflow, as water could bypass the tunnel-like emitter. Fine-tuning of the water outflow and/or water pressure thus fails to be realised in such kind of continuous emitter.
Furthermore, a lower cost of production and an easier production of a pressure compensating elongated flat sheet in a drip irrigation hose is also needed.
Therefore, there remains a need to create a new, easier production, low cost, elongated-typed emitter such as a strip to emit water in an even shorter distance while able to maintain water pressure and/or water flow rate over a wide distance. Furthermore, water pressure in the drip irrigation hose that is better fine-tuned remained a challenge to be realised.
The inventors of the present invention have surprisingly found out that the above-formulated need can be met by creating a specially-designed strip that is pressure-compensated, elastic, able to fine-tune water flow rate and regulate water pressure. The strip is provided to be able to simultaneously response, regulate and reduce water flow rate and/or water pressure thanks to an array of specially designed profiles in a regulating section of the strip. This advantageously allows for a lower cost, of production, shorter labyrinth segment, hence allowing for more repetitive labyrinth segments and more water outlets within a shorter distance. Hence, water is able to be distributed through outlets on the drip irrigation hose in a shorter distance, for example, less than about 10 cm, or even less than 5 cm without affecting the water flow rate of the pressure compensating strip. Furthermore, water pressure and water outflow can be better fine-tuned thanks to the different profiles provided in the regulating section of the strip, as water flows through the entire length of labyrinth segment of the strip. Under higher water pressure condition, certain profiles are pushed towards the hose, thereby creating additional barrier within the labyrinth. This enables water pressure to be regulated in an optimal condition, allowing fine-tuning of water outflow condition and water pressure in the strip.
In a first aspect, the present invention therefore relates to a strip for distributing water, said strip has a repetitive labyrinth segment, wherein a plurality of profiles are provided to the base of the strip, said labyrinth segment comprises: a water input section; a regulating section arranged downstream from the water input section, wherein said regulating section is provided to regulate water flow rate of the strip in response to water pressure of a hose; a discharge section arranged downstream from the regulating section, wherein said discharge section is provided with deflection-resistant reinforcement means. In addition to the advantages described above, the discharge section of the strip according to the present invention allows water to be evenly distributed in a controllable manner, as reinforcement means is provided to reduce frequency of deflection caused by water pressures which exits from the outlets.
In a second aspect, the present invention relates to a pressure compensating drip irrigation hose comprising the aforementioned strip as described herein.
According to a variant of the present invention, said strip is made of at least one elastomeric material. This advantageously allows for not only a lower cost of production and easier production, it allows for the drip irrigation hose to be arranged in all possible positions without hindering the flexibility of the hose.
According to yet another variant of the present invention, the water input section is provided with a filter means. This advantageously allows for water to be filtered before entering into the regulating section.
According to another variant of the present invention, the distance between the profiles in the input section are less than the distance between the profiles in the regulating section. This advantageously prevents particles larger than the gap between profiles in the water input section to be entered into the regulating section of the strip.
According to one preferred embodiment of the present invention, the strip has two rails, forming side walls of the strip. The rails could exist in both the regulating section and the discharge section. This allows water to enter into the strip only through the water input section which has a filter means to filter out certain particles having diameter larger than the gap between profiles of water input section. The filtered water then flows alone the labyrinth segment.
According to one preferred embodiment of the present invention, said profiles in the regulating section comprises a first profiles, a second profiles and/or farther profiles, wherein the first profiles is a rectangular-shaped block whereas the second profiles have a wedge shape. The first profiles, the second profiles and/or further profiles in the regulating section have a barrier-like partition structure extended from the rails of the strip. The first profiles are advantageously designed to set a limitation of a fixed volume of water flowing in the strip. This allows for a certain predetermined water flow rate and/or water pressure flowing in the strip. This prevents voids of the strip to collapse under situation where water pressure is extremely high in the hose. The second profiles of the regulating section are advantageously designed to be able to response, regulate and reduce water pressure and/or water flow rate of the strip according to water pressure within the drip irrigation hose. Importantly, in the present invention, water flows along the entire labyrinth segment of the strip. On one hand, the first profiles allow for a maximum volume of water flowing in the strip; on another hand, the second profiles fine-tune water pressure and/or water flow rate of the strip depending on the water pressure of the hose. Such combination of at least two different profiles in the regulating section of the strip thus allows an optimal pressure compensating drip irrigation hose to be realised.
According to one preferred embodiment of the present invention, the entire top surface of the first profiles opposite to the base of the strip are connected to an inner part of a hose. This allows said type of first profiles to be fixed permanently between the strip and the hose, thus allowing a fixed volume of water flowing within the strip.
According to one embodiment of the present invention, the profiles in the regulating section are provided in an alternative and/or regular or irregular fashion throughout the repeated labyrinth segment. In order to allow water flow rate of the strip and its response to water pressure of the hose to be regulated in a wider range, higher number of the second profiles having a wedge shape than the first profiles could be arranged in the regulating section of the strip. Contrary, in order to better fine-tune water outflow (water flow rate in the strip) and its response to the water pressure of the hose, less number of the second profiles than the first profiles can be used to achieve the aforementioned goal.
According to one preferred embodiment of the present invention, the discharge section is provided with interconnected reinforcements to increase the resistance of deflection.
According to another preferred embodiment of the present invention, the interconnected reinforcements are provided at the base of the strip. This fortifies said section, allowing for stronger structure.
According to one preferred embodiment of the present invention, the interconnected reinforcements have height less than the top surface of the rails of the strip so that their influence on disturbing water flow rate is minimised.
According to yet another preferred embodiment of the present invention, the strip is provided at an inner surface of the drip irrigation hose.
According to one preferred embodiment of the present invention, the strip is made up of material less stiff than the drip irrigation hose so, that the flexibility of the hose is not affected by the strip operatively connected within.
According to one preferred embodiment of the present invention, at least one outlet of the hose is provided at the discharge section of the strip. This allows for instaneously water outflow.
According to the present invention, the outlet is an open-end outlet or a slit. Both open end outlet and slit outlet allow water to be emitted easily Furthermore, slit outlets further prevent the roots of the plants from growing into the drip irrigation hose.
Thanks to the present uniquely designed strip having a water input section, a regulating, section and a discharge section which form a labyrinth segment, the labyrinth segment of the strip according to the present invention is able to be designed in various length, for instance less than 10 cm. It is possible to be less than 8 cm. It is also designed for less than 5 cm without affecting the functionality of the pressure compensating strip and its water flow rate as well as fine-tuning its response to water pressure of the hose.